Cutting device for looms

ABSTRACT

A device to perform the cutting of weft threads in shuttleless looms provided with grippers for carrying the weft threads, in which a cutting blade arranged substantially perpendicular to the weft threads co-operates with a counter blade in respect to which it is operated under the control of cam means. In a first embodiment the blade is perpendicular and in a second embodiment it is parallel to the working path of the grippers.

United States Patent- [191 Serturini June 4, 1974 (5 1 CUTTING DEVICEFOR LOOMS [75] Inventor:

[73] Assignee: Somet Societa Meccanica Tessile S.p.A., Colzate, Italy[22] Filed: June 21, 1972 [21] Appl. No.: 264,919

Giuseppe Serturini, Gomo, Italy 301 Foreign Application Priority DataJune 21. l'97.1- Italy.' 26139/71 521 U.S.CI. ..139/302 [51 1nt.Cl .Q..D03d47/36 [58] Fieldof Search. 139/122 R, 302, 303, 263-268 [56]References Cited UNITED STATES PATENTS 3,376,900 4/1968 Payne 139/2633,621,885 11/1971 Egloff et a1. 139/302 FOREIGN PATENTS OR APPLICATIONS544,678 2/1956 Italy 139/303 Primary Examiner-Henry S. Jaudon Attorney,Agent, or FirmYoung & Thompson [5 7] ABSTRACT A device to perform thecutting of weft threads in shuttleless looms provided with grippers forcarrying the weft threads, in which a cutting blade arrangedsubstantially perpendicular to the weft threads cooperates with acounter blade in respect to which it is operated under the control ofcam means. In a first embodiment the blade is perpendicular and in asecond embodiment it is parallel to the working path of the grippers.

6 Claims, 5 Drawing Figures PATENTEBJUH 41974 SHEET 1' [IF 4 CUTTINGDEVICE FOR LOOMS BACKGROUND OF THE INVENTION It is known that in theshuttleless looms for the continuons feeding of the weft of the typeprovided with weft carrying grippers for exchanging the weft threads atthe center of the shed, the wefts, selected at one end of the shed, arecaught by the carrier gripper, are cut and then carried into the shed.The cutting maybe performed in various manners and by means of deviceswhich operate in many ways, but it is generally carried out by a cuttingelement which operates along the running direction of the weft and ofthe grippers, i.e., lengthwise with respect to the loom. That involvessome inconveniences concerning both' the cutting of the weft, which isnot always carried out correctly, and the engagement of the weft itselfon the carrier gripper, which may tumout to faulty or may occur withdelay, so that it may happen that the weft is lost while the gripperruns or that double wefts are picked.

The present invention now concerns a device for cutting wefts, whichoperates under positive control and reliably and with all types orcounts of weft threads and assuring in a definitely improved way thatthe weft thread is engaged on the carrier gripper provided for carryingit into the shed.

that a cutting blade, which is provided substantially perpendicular tothe weft thread,cuts said thread in cooperation with a counter-blade,and is operated with respect to the latter under the control of cammeans.

In a preferred embodiment the counter-blade isprovided at the end of ahooked element guiding and retaining the weft thread, whichis supportedby a lever swinging around an axis parallel to the working path of thegrippers, while the means which support the cutting blade, and whichswing aroundan axis perpendicular to the working path of thegrippers,are associated with said lever.

. BRIEF DESCRIPTION OF THE DRAWINGS deviceshown in FIGS. 1 and 2 takenfrontally with respect to said device; and

FIGS. 4 and 5 are views similar to those shown in FIGS. 1 and 2 whichshow a different embodiment of the device according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As FIG. 1 shows, the device 1according to the invention is mounted on the feeding side of ashuttleless loom for the continuous feeding of the weft, in replacementof a hooked lever of an already known type, for guiding and retainingweft threads and for cutting the same in the conventional way. Thedevice l'is provided in proximity to the inlet of the shed, after theselecting devices 2 and the presenting devices 3.

The device consists of a lever body 4 which is pivotally connected withthe fixed structure of the loom, through a shaft 5, and which ends in adouble bellcrank arm 6, provided in an essentially horizontal position,from which, in an essentially vertical position and perpendicular to theworking path of the grippers as well as to the weft threads, a guidingand threads retaining hooked element 7 projects downwards, ending in acounter-blade 7. The above described part of the device is mounted, in aknown way, for swinging in a vertical plane around shaft 5 under thecontrol of cam means. To this purpose the end of lever 4 bears a camfollower 8 which co-operates with a front cam 9 of the cam-group 10 cfthe device.

According to the invention, a shaft 11 rotates in a seat in the centralpart of the lever body 4.'Said shaft is connected at one end with aroller cam follower 12 by means of a stirrup l3 bearing a seat 14provided for arettrn spring 15 acting against the body 4.-At the otherend of shaft 11 is connected a double bell-crank lever 16, mountedsubstantially parallel to the arm 6, to the end of said lever beingpivotally connected the blade 17. The latter is mounted by means of pin18 in a hole 19 of the lever 16, it being possible to adjust it, and isoperated by a blade spring 20 which pushes the cutting edge 17' of blade17 into close contactwith the hooked counter-blade element 7, 7

The roller cam follower 12, mounted on stirrup 13 by means of a swingingbearing, is engaged by a front cam 21 which is one of-group 10 and isprovided in front of front cam 9, both cams moving independently fromone another, since each of them responds in its own way to the generalmovement of the loom.

The hooked element 7, as it is clearly shown in FIGS. 1 and 2, has apart of it formed into a recess to guide and retain the thread. Saidpart is rounded, while the cutting edge of counter-blade 7 is providedonly at the end of the element, beyond its recess.

In the embodiment shown in FIGS. 4 and 5, in which the same numeralsrefer to the same parts, the hooked element 7 is provided in a differentposition, it being still substantially vertical, but on one sideperpendicular to the path of the weft thread and on the other sideparallel to the working path of the grippers. Furthermore, differentlyfrom the above described embodiment, shaft 11 carries at its end closeto the cam group 10 a small support 22 provided with a locking screw 23for a cam follower 24 and a return spring 25 operating between the body4, and the small support 22. At the other end of shaft 11 the doublebell-crank lever 16 carries at one end a blade 26 provided in the sameposition as the hooked element 7 for co-operating in cutting with thecutter side of said hooked element. Cam

follower 23 co-operates with cam 27 which belongs to.

, caught by the presenting device 3, is only slightly inserted into thecarrier gripper P by the gripping means with which it has to be engagedand it is still connected owing to the control of cam 9, so that thehooked element 7 guides and retains thread F in its recess. in theoperating stage which immediately follows the stage illustrated in FIG.1, cam 21 or cam 27 engage, by means of their protrusion (21 or 27' camfollowers 12 or 23, thus causin shaft 11 to rotate against the action ofsprings 15 or 25 in the direction which causes the lowering of blade 17or of blade 26. Then, the lowered blade with its cutting edge engagesthe weft thread F and cuts it, in the most safe manner, against theendpart of element 7 on which counter-blade 7 is provided,.said bladeco-op erating with the counter-blade.

Immediately before all the above happens, gripper P move into asufficiently forward-position as to obtain the safe insertion of threadF into the holding means of said gripper. Therefore, the cut is carriedout only after said insertion is performed.

The insertion is guaranteed by the fact that thread F, before it is cut,is supported by a rounded surface of element 7, so that there is nopossibility that the cut is carried out before or at the same time asthe insertion.

'Of course, using a cam control to swing both the whole device and thecutting blade, allows one to set practically in, a perfect waytheoperating times of the guiding and retaining hook and of the cuttingblade, and therefore to obtain the best working of the loom for thefeeding of the carrier gripper.

Besides, many other advantages are allowed by the device which is theobject of the present invention:

First of all an absolute certainty is reached as to carrying out, at anyspeed of the loom, the cut of the weft threads, even when high countfabrics are worked.

Further, there is the absolute certainty that the cut is carried outwhen the weft thread was already inserted into the carrier gripper, aswas said above. As a consequence, the possibility is excluded thatdouble wefts are formed.

The possibility is offered to remarkably reduce the size of the cuttingelement and this fact, together with the particular form it was given,reduces the income nience, which is often present in the known cuttingdevices, that non-selected weft threads are unexpectedly cut by mistake,they were engaged by the cutting element.

Finally, the heretofore described device, in spite of the complexity andprecision of the operation preformed, is extremely simple, rational,easy to be manufactured and adjusted and remarkably compact.

vI claim: 1

1. In a continuous weft feeding loom having a shed and grippers carryingweft threads into the shed and transferring said threads at the centerof the shed to further grippers entering the shed from theoppositedirection, and weft thread cutting means oscillable about an axisparallel to the path of the grippers between a rest position and acutting position and comprising a blade and a counter blade and means tomove said blade and counter blade relative to each other to cut the weftthread; the improvement comprising means for moving said counter bladerelative to said blade about an axis perpendicular to said path to thegrippers,

means to effect said movement of said cutting means to said cuttingposition and said relative movement of said blade and counter blade tocut said thread when said grippers move toward said center of the shed,and separate first and second rotary cam means to control the movementof said blade and counter blade.

2. Apparatus as claimed in claim I, said cutting means comprising alever mounted for oscillation about an axis parallel to said path of thegrippers, said lever terminating in a hook element for guiding andretaining the weft threads, said counter blade being disposed close tothe free end of said hook element.

3. Apparatus as claimed in claim 2, and spring means interconnectingsaid blade and counter blade.

4. Apparatus as claimed in claim 2, in which said hook element has arounded portion for guiding-and retaining the weft threads.

5. Apparatus as claimed in claim 1, in which said blade is perpendicularto said path of the grippers.

6, Apparatus as claimed in claim 1, in which said blade is parallel tothe path of the grippers.

1. In a continuous weft feeding loom having a shed and grippers carryingweft threads into the shed and transferring said threads at the centerof the shed to further grippers entering the shed from the oppositedirection, and weft thread cutting means oscillable about an axisparallel to the path of the grippers between a rest position and acutting position and comprising a blade and a counter blade and means tomove said blade and counter blade relative to each other to cut the weftthread; the improvement comprising means for moving said counter bladerelative to said blade about an axis perpendicular to said path to thegrippers, means to effect said movement of said cutting means to saidcutting position and said relative movement of said blade and counterblade to cut said thread when said grippers move toward said center ofthe shed, and separate first and second rotary cam means to control themovement of said blade and counter blade.
 2. Apparatus as claimed inclaim 1, said cutting means comprising a lever mounted for oscillationabout an axis parallel to said path of the grippers, said leverterminating in a hook element for guiding and retaining the weftthreads, said counter blade being disposed close to the free end of saidhook element.
 3. Apparatus as claimed in claim 2, and spring meansinterconnecting said blade and counter blade.
 4. Apparatus as claimed inclaim 2, in which said hook element has a rounded portion for guidingand retaining the weft threads.
 5. Apparatus as claimed in claim 1, inwhich said blade is perpendicular to said path of the grippers. 6.Apparatus as claimed in claim 1, in which said blade is parallel to thepath of the grippers.